Two-cycle internal-combustion engine



Jan. 4 1927'.

G. HELD TWO-CYCLE INTERNAL COMBUSTION ENGINE Fil e d Dec. 11. 1924 Patented Jan. 4, 1927.

UNITED STATES 1,613,226 PATENT OFFICE.

GEORGES HELD, OF PARIS, FRANCE, ASSIGNOR TO ALBERT L. LEGRAND, OF PARIS,

FRANCE.

TWO-CYCLE INTERNAL-COMEUSTION ENGINE.

Application filed December 11, 1924, Serial No. 755,349, and in France December 29, 1923.

tion of the combustible mixture at low com-J pression.

The current types of two-cycle motors can be divided into the two following groups:

(1) Motors with high compression, of which the diagram is similar to that of the Diesel engine. Because of the high initial pressure these motors made a heavy constructionnecessary, they are heavy and cannot be built as light models.

(2) Motors with a medium compression, with the outstanding feature of some part which is kept glowing. Before these motors can be started this part must be heated and the increased temperature is not without danger. The average pressure in these motors is fairly weak, which leads to very large piston dimensions and increases the weight accordingly.

The aim of this invention is the construction of a light motor, which can work with a medium compression, has no heated parts and can be driven with heavy fuels. The attached schematic drawings 1 and 2 Show:

' Fig. l a cross section of a complete motor cylinder built according to the invention.

Fig. 2 the arrangement of a three-cylinder motor, showing the location of the pipings with regard to the cylinder.

In Figure 1 the cylinder is marked 11; .it is equipped with two pipes 12 and 13, the function of which will be described later. The piston is markedl and the cylinder head with 3. In the middle of the top part of the head an injection device 5 of the usual type is provided for liquid fuels. Thelower part of the cylinder head is cylindrical and of a smaller diameter than the piston. The top has the shape of a hollow half globe, the

axis of which coincides with the axis of thcl cylinder 11.

The piston 1 at the top is worked cylindrically (2); the diameter at the top is less than the lower part of the cylinder head, so that at'the end of the piston stroke a tubeshaped space 4 is formed, whose function will be described further down.

This part of the piston is also worked in such a shape, that it forms a hollow half globe of the same diameter as the one on the cylinder head.

At the end of the piston stroke the com- I 'bustion chamber therefore has the shape of a hollow globe, as it is shown on the diagram.

The necessary scavenging air is furnished vby a centrifugal ventilator or a pump, which is shown on the drawing as 6. Before the air enters into the cylinder, it passes the tubes 7 of a preheater 8, which is effectively heated by the exhaust gas, which are shown to leave at 8'. The air, which has been preheated in this manner enters into a chamber 9, from where it passes over into the cylinder as soon as thisis made possible by a proper valve system; which is not shown on the drawing.

The functioning of the motor is as follows: During the compression period the temperature of the air, which has been preheated in the preheater 8, rises quickly and at the end of the compression stroke it is high enough to ensure self ignition of the: fuels used. By a proper choice of the initial air temperatureit is possible to reach the de sired temperature with a moderate compression. Before the end of the compression the head of the piston 2 enters into the combustion chamber and compresses the air strongly in the ring-shaped space 10, because of the large resistance opposed to its passage througlrthe ring-shaped part 3.

\Vhen the air enters through the chamber 4 into the combustion chambers its speed is considerable and its direction is practicallytangential to the circumference of the globe.

Because of this peculiar feature the air within the globe is brought to a whirling movement, as it is indicated by arrows. When the injection ofthe fuel takes 'place, it hits on this whirling circle, which has all the properties of ordinary dynamicstability.

- The injection of the fuel into the whirltakes place in the direction b -a and the parts of the fuel, which are completely surrounded by the whirl, takes a direction which can be indicated by the are 6-0, which approaches the center of the globe.

This provides a complete and thorough mixture and'facilitates ignition.

The results mentioned above have in every case been obtained by aproper size of the chambers 4 and 10, which insure the forma tion of the whirls. Naturally the speed increases in proportion} to the decrease in the size of the opening 4, under otherwise equal conditions.

The features are, therefore, that the ignition temperature has been reached in the combustion chamber when the fuel is injected and the complete combustion is safeguarded by the complete envelopment of all particles in the whirling mass of air. As

light motors for airshi'ps and automotive vehicles possible.

The heating of the scavenging the heat of the exhaust gaspermits a reduction in the dimensions of the air pump, if

one takes into consideration that the volume of the scavenging air increasesinproportion' to its rising temperature.

'I claim:

In an internal combustion engine, a cylinv the limit of a r throughder, a cylinder head for said cylinder, said head being provided with an inverted substantially semi-toroidal channel, and a pisg ton adapted to reciprocate in said cylinder,

the top of said piston being provided with a cylindrical extension, the diameter of which is slightly less than the outer diameter of the channel in said cylinder head, the

to of said extension being provided with a .su stantially semi-toroidal channel oppositely disposed to the channel in said head, said channels having genetrices of equal diameters and having their directrices coinciding with each other and with the axis of said piston whereby as the piston approaches its upward travel a toroidal chamber will be formed and the air coinpressed by said piston will beforc'ed .into.

said chamber at a tangent to the 'outer-diams eter thereof. Y .In testimony whereof hereunto aflix my signature.

' 'GEORGES' HELD. I 

